nedash says:

<asp:LinkButton ID="LinkbtnclassC" runat="server"  CssClass="lbldasteM"

                                              CommandArgument='<%# Eval("Name") %>' OnClick="LinkbtnclassC_Click"><%# Eval("Name") %></asp:LinkButton>

Check you have given Id as LinkbtnclassC and in your code you finding it using Id Linkbtnclass1.Please refer below code.

C#

foreach (DataListItem dlItems1 in DLclassC.Items)
{
    LinkButton lb1 = dlItems1.FindControl("LinkbtnclassC") as LinkButton;
    lb1.ForeColor = ColorTranslator.FromHtml("#646464");
}
(item1.FindControl("LinkbtnclassC") as LinkButton).ForeColor = ColorTranslator.FromHtml("#fb00c2");

ok

I changed code it doesn't make error but when I select text from LinkbuttonC (DlclassC) it doesn't change text color...

It shows all text with forecolor...

Hi,

Please refer below code,It is working fine.

HTML

<asp:DataList ID="DLclass" runat="server">
    <ItemTemplate>
        <asp:LinkButton ID="Linkbtnclass" runat="server" CssClass="lbldasteM" CommandArgument='<%# Eval("Name") %>'
            OnClick="Linkbtnclass_Click"><%# Eval("Name") %></asp:LinkButton>
        <div id="MM31">
        </div>
    </ItemTemplate>
</asp:DataList>
<asp:DataList ID="DLclassC" runat="server">
    <ItemTemplate>
        <asp:LinkButton ID="LinkbtnclassC" runat="server" CssClass="lbldasteM" CommandArgument='<%# Eval("Name") %>'
            OnClick="LinkbtnclassC_Click"><%# Eval("Name") %></asp:LinkButton>
        <div id="MM31">
        </div>
    </ItemTemplate>
</asp:DataList>

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Id", typeof(int)),
                    new DataColumn("Name", typeof(string)),
                    new DataColumn("Country",typeof(string)) });
        dt.Rows.Add(1, "John Hammond", "United States");
        dt.Rows.Add(2, "Mudassar Khan", "India");
        dt.Rows.Add(3, "Suzanne Mathews", "France");
        dt.Rows.Add(4, "Robert Schidner", "Russia");
        DLclass.DataSource = dt;
        DLclass.DataBind();
        DLclassC.DataSource = dt;
        DLclassC.DataBind();
    }
}

protected void Linkbtnclass_Click(object sender, EventArgs e)
{
    DataListItem item = (DataListItem)(sender as LinkButton).NamingContainer;
    foreach (DataListItem dlItems in DLclass.Items)
    {
        LinkButton lb = dlItems.FindControl("Linkbtnclass") as LinkButton;
        lb.ForeColor = ColorTranslator.FromHtml("#646464");
    }
    (item.FindControl("Linkbtnclass") as LinkButton).ForeColor = ColorTranslator.FromHtml("#fb00c2");
}

protected void LinkbtnclassC_Click(object sender, EventArgs e)
{
    DataListItem item1 = (DataListItem)(sender as LinkButton).NamingContainer;
    foreach (DataListItem dlItems1 in DLclassC.Items)
    {
        LinkButton lb1 = dlItems1.FindControl("LinkbtnclassC") as LinkButton;
        lb1.ForeColor = ColorTranslator.FromHtml("#646464");
    }
    (item1.FindControl("LinkbtnclassC") as LinkButton).ForeColor = ColorTranslator.FromHtml("#fb00c2");
}

Screenshot

this is my code:

protected void Linkbtnclass_Click(object sender, EventArgs e)
{
    BindDataListT(DLclassC, "classTI_documentry");
    DataListItem item = (DataListItem)(sender as LinkButton).NamingContainer;
    foreach (DataListItem dlItems in DLclass.Items)
    {
        LinkButton lb = dlItems.FindControl("Linkbtnclass") as LinkButton;
        lb.ForeColor = ColorTranslator.FromHtml("#646464");
    }
   (item.FindControl("Linkbtnclass") as LinkButton).ForeColor = ColorTranslator.FromHtml("#fb00c2");

}
protected void LinkbtnclassC_Click(object sender, EventArgs e)
{
    BindDataListT(DLclassC, "classTI_documentry");
    DataListItem item1 = (DataListItem)(sender as LinkButton).NamingContainer;
    foreach (DataListItem dlItems1 in DLclassC.Items)
    {
        LinkButton lb1 = dlItems1.FindControl("LinkbtnclassC") as LinkButton;
        lb1.ForeColor = ColorTranslator.FromHtml("#646464");
    }
(item1.FindControl("LinkbtnclassC") as LinkButton).ForeColor = ColorTranslator.FromHtml("#fb00c2");
}

but it doesn't worked it just do Linkbtnclass_Click ...